Congestive heart failure (CHF) has been associated with elevated biomarker levels reflecting chronic low-grade inflammation. YKL-40 is a biomarker with increasing levels in patients with cardiovascular disease (CVD) of increasing severity. Furthermore, YKL-40 is associated with all-cause and cardiovascular mortality. We investigated plasma YKL-40 levels in patients with CHF and evaluated the possible predictive value with respect to overall mortality and recurrent cardiovascular outcomes.